/*
 * Copyright (C) 2020 original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
 * in compliance with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */

package vip.justlive.easyproxy.server.handler;

import java.nio.ByteBuffer;
import lombok.RequiredArgsConstructor;
import vip.justlive.easyproxy.core.context.Metrics;
import vip.justlive.easyproxy.core.context.ServerProxyContext;
import vip.justlive.easyproxy.core.protocol.ProxyData;
import vip.justlive.oxygen.core.net.aio.core.AioHandler;
import vip.justlive.oxygen.core.net.aio.core.AioListener;
import vip.justlive.oxygen.core.net.aio.core.ChannelContext;

/**
 * 服务端代理处理单元
 *
 * @author wubo
 */
@RequiredArgsConstructor
public class ProxyHandler implements AioListener, AioHandler {

  private final ServerProxyContext proxy;
  private final ChannelContext remote;

  @Override
  public Object decode(ByteBuffer buffer, int readableSize, ChannelContext channelContext) {
    Metrics.metrics(proxy.getPort()).getReadBytes().addAndGet(readableSize);
    byte[] data = new byte[readableSize];
    buffer.get(data);
    return data;
  }

  @Override
  public ByteBuffer encode(Object data, ChannelContext channelContext) {
    byte[] bs = (byte[]) data;
    Metrics.metrics(proxy.getPort()).getWriteBytes().addAndGet(bs.length);
    return ByteBuffer.wrap(bs);
  }

  @Override
  public void onConnected(ChannelContext channelContext) {
    Metrics.metrics(proxy.getPort()).getServerChannels()
        .set(channelContext.getGroupContext().getChannels().size());
    remote.write(ProxyData.connect(proxy.getRemote(), proxy.getId(), channelContext.getId()));
  }

  @Override
  public void onClosed(ChannelContext channelContext) {
    Metrics.metrics(proxy.getPort()).getServerChannels()
        .set(channelContext.getGroupContext().getChannels().size());
    remote.write(ProxyData.closeChannel(proxy.getId(), channelContext.getId()));
  }

  @Override
  public void handle(Object data, ChannelContext channelContext) {
    byte[] bs = (byte[]) data;
    remote.write(ProxyData.transfer(bs, proxy.getId(), channelContext.getId()));
  }
}
